Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Port boundary conditions

Please login with a confirmed email address before reporting spam

Hello all,
Till today, I worked with COMSOL 3.5 to examine planar waveguides. I used match boundary conditions for excitation and termination at both sides of the waveguide in the RF frequency domain. This boundary condition worked just fine, but I find it very difficult to implement the same BC in COMSOL 4.3 or newer versions. For now, I understood already that I have to use port boundary conditions, and set the power instead of the amplitude. However, I didn't really get the settings for excitation and termination. Upon exictation I switch on the "wave excitation at this port" and set the amplitude function (In my case it is of Hz) and the power (I do not set the phase). I actually think I got it right over here. On the other side of the waveguide (The termination port) , I switched off the excitation, and set the magnetic field to zero (as was in the match BC). In this case I get an error message from COMSOL. I also tried to use the same excitation field (Hz) in the termination port, and got some messy results.
I really don't understand how to use it correctly. Anyone?
Thanks in advance,
Tal.

I attached a simple model of PEC-dielectric-PEC waveguide which is excited on its left end with simple known analytic mode to demonstrate the issue.




0 Replies Last Post Jun 1, 2015, 10:59 a.m. EDT
COMSOL Moderator

Hello Tal Weiss

Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.

If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.